The subject matter disclosed herein relates to a check valve and, more particularly, to a check valve having petals with lift generating elements, such as airfoils, to counterbalance petal weight.
In bleed systems where fluid pressure can be tapped off from either a high pressure stage compressor or a low pressure stage compressor, a check valve is needed to prevent the high pressure stage bleed air from backflowing into the low pressure stage compressor. This check valve often includes petals that occupy closed positions when the high pressure stage bleed air has a higher pressure than the low pressure stage compressor whereby the high pressure stage bleed air is prevented from backflowing into the low stage compressor. These petals open when the pressure of the low pressure stage compressor exceeds that of the high stage bleed air.
The check valves are often disposed in a vertical arrangement such that the petals sit on washer elements that bear the petal weight. As such, when the petals open and close, contact between the petals and the washer elements leads to wear and damage of the washer elements. This, in turn, leads to contact between the petals and the housing of the check valve.